Been posting to the blog Hammer of Judgement in comments, but thought I ought to excerpt the last comment here too:
#1: It doesn’t matter WHY they drive less, if you’re just measuring the regressivity of the gas tax. Whether it’s because they don’t have to, don’t want to, or CAN’T is irrelevant.
#2: Texas “highway system” comprises only roads with route shields on them, and even then, substantial donations in the form of property and sales taxes are required these days to get anything built. In addition, in Texas, most major arterials inside cities are NOT part of the state highway system, and thus get ZERO gas tax dollars.
This is not something you want to dispute me on, it’s the closest thing to a specialty I have. Here’s some starter links for you:
#3: On anectdotes – the studies I cited aren’t available in their full form on the web (to me or you), but they go WAY beyond anectdotal data, since there are real studies behind those quotes, unlike most of the people who assert the gas tax’ regressivity.
#4: I don’t know where the 15% figure comes from; but even if true, the STATED REASON most people harp on the supposed regressivity of the gas tax is concern for the poorest people, not the middle class. Thus, showing that it’s regressive across middle and high incomes but NOT low incomes serves to refute the essential point.
Note that I cover the topic of roadway funding extensively in this category, including “what roads get gas taxes and what don’t”, “how do we pay for major roads”, “why does the state effectively subsidize the suburbs through the gas tax”, etc.